<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<HTML>
<HEAD>
<TITLE>Class Template device</TITLE>
<LINK REL="stylesheet" HREF="../../../../boost.css">
<LINK REL="stylesheet" HREF="../theme/iostreams.css">
</HEAD>
<BODY>
<!-- Begin Banner -->
<H1 CLASS="title">Class Template <CODE>device</CODE></H1>
<HR CLASS="banner">
<!-- End Banner -->
<DL class="page-index">
<DT><A href="#description">Description</A></DT>
<DT><A href="#headers">Headers</A></DT>
<DT><A href="#reference">Reference</A></DT>
</DL>
<HR>
<A NAME="description"></A>
<H2>Description</H2>
<P>
The class template <CODE>device</CODE>, its subcass <CODE>wdevice</CODE> and their specializations <CODE>source</CODE>, <CODE>sink</CODE>, <CODE>wsource</CODE> and <CODE>wsink</CODE> are provided by the Iostreams library to ease the definitions of new models of the various <A HREF="../guide/concepts.html#device_concepts">Device Concepts</A>. These templates and <CODE>typedef</CODE>s are inteded to be used as base classes for user-defined Devices. They supply the member types <CODE>char_type</CODE> and <CODE>category</CODE> used by the Iostreams library.
</P>
<P>
The supplied <CODE>category</CODE> member is convertible to <A HREF="../guide/traits.html#category_tags"><CODE>closable_tag</CODE></A> and to <A HREF="../guide/traits.html#category_tags"><CODE>localizable_tag</CODE></A>. This allows users to define models of the concepts <A HREF="../concepts/closable.html">Closable</A> and <A HREF="../concepts/closable.html">Localizable</A> simply by providing definitions of member functions <CODE>close</CODE> and <CODE>imbue</CODE>.
</P>
<A NAME="headers"></A>
<H2>Headers</H2>
<DL class="page-index">
<DT><A CLASS="header" HREF="../../../../boost/iostreams/concepts.hpp"><CODE><boost/iostreams/concepts.hpp></CODE></A></DT>
</DL>
<A NAME="reference"></A>
<H2>Reference</H2>
<A NAME="synopsis"></A>
<H3>Synopsis</H3>
<PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> boost{ <SPAN CLASS="keyword">namespace</SPAN> iostreams {
<SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> Mode, <SPAN CLASS="keyword">typename</SPAN> Ch = <SPAN CLASS="keyword">char</SPAN>>
<SPAN CLASS="keyword">struct</SPAN> <A CLASS="documented" HREF="#description">device</A>;
<SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> Mode, <SPAN CLASS="keyword">typename</SPAN> Ch = <SPAN CLASS="keyword">wchar_t</SPAN>>
<SPAN CLASS="keyword">struct</SPAN> <SPAN CLASS="defined">wdevice</SPAN> : device<Mode, Ch> { };
<SPAN CLASS="keyword">typedef</SPAN> device<input> <SPAN CLASS="defined">source</SPAN></A>;
<SPAN CLASS="keyword">typedef</SPAN> device<output> <SPAN CLASS="defined">sink</SPAN>;
<SPAN CLASS="keyword">typedef</SPAN> wdevice<input> <SPAN CLASS="defined">wsource</SPAN>;
<SPAN CLASS="keyword">typedef</SPAN> wdevice<output> <SPAN CLASS="defined">wsink</SPAN>;
<SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="#template_params">Mode</A>, <SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="#template_params">Ch</A> = <SPAN CLASS="keyword">char</SPAN>>
<SPAN CLASS="keyword">struct</SPAN> <A CLASS="documented" HREF="#description">device</A> {
<SPAN CLASS="keyword">typedef</SPAN> Ch char_type;
<SPAN CLASS="keyword">typedef</SPAN> <A STYLE="text-decoration:none" HREF="#category"><SPAN CLASS="omitted">see below</SPAN></A> category;
<SPAN CLASS="keyword">void</SPAN> <A CLASS="documented" HREF="#close">close</A>();
<SPAN CLASS="keyword">void</SPAN> <A CLASS="documented" HREF="#close">close</A>(std::ios_base::openmode);
<SPAN CLASS="keyword">void</SPAN> <A CLASS="documented" HREF="#imbue">imbue</A>(<SPAN CLASS="keyword">const</SPAN> std::locale&);
};
} } <SPAN CLASS="comment">// End namespace boost::io</SPAN></PRE>
<A NAME="template_params"></A>
<H4>Template parameters</H4>
<TABLE STYLE="margin-left:2em" BORDER=0 CELLPADDING=2>
<TR>
<TR>
<TD VALIGN="top"><I>Mode</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
<TD>A <A HREF="../guide/modes.html#mode_tags">mode tag</A>.</TD>
</TR>
<TR>
<TD VALIGN="top"><I>Ch</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
<TD>The character type</TD>
</TR>
</TABLE>
<A NAME="category"></A>
<H4><CODE>device::category</CODE></H4>
<PRE CLASS="broken_ie"> <SPAN CLASS="keyword">typedef</SPAN> <SPAN CLASS="omitted">see below</SPAN> category;</PRE>
<P>
A category tag convertible to <A HREF="#template_params"><CODE>Mode</CODE></A>, <A HREF="../guide/traits.html#category_tags"><CODE>device_tag</CODE></A>, <A HREF="../guide/traits.html#category_tags"><CODE>closable_tag</CODE></A> and <A HREF="../guide/traits.html#category_tags"><CODE>localizable_tag</CODE></A>.
</P>
<A NAME="close"></A>
<H4><CODE>device::close</CODE></H4>
<PRE CLASS="broken_ie"> <SPAN CLASS="keyword">void</SPAN> <A CLASS="documented" HREF="#close">close</A>();
<SPAN CLASS="keyword">void</SPAN> <A CLASS="documented" HREF="#close">close</A>(std::ios_base::openmode);</PRE>
<P>
Both overloads are implemented as no-ops. The second is available only if <A HREF="#template_params">Mode</A> is convertible to <A HREF="../guide/modes.html#mode_tags"><CODE>bidirectional</CODE></A>. The first is available only if Mode is <I>not</I> convertible to <A HREF="../guide/modes.html#mode_tags"><CODE>bidirectional</CODE></A>.
</P>
<P>
Required by <A HREF="../concepts/closable.html">Closable</A>.
</P>
<A NAME="imbue"></A>
<H4><CODE>device::imbue</CODE></H4>
<PRE CLASS="broken_ie"> <SPAN CLASS="keyword">void</SPAN> <A CLASS="documented" HREF="#imbue">imbue</A>(<SPAN CLASS="keyword">const</SPAN> std::locale&);</PRE>
<P>
Implemented as a no-op. Required by <A HREF="../concepts/localizable.html">Localizable</A>.
</P>
<!-- Begin Footer -->
<HR>
<P CLASS="copyright">Revised 02 Feb 2008</P>
<P CLASS="copyright">© Copyright 2008 <a href="http://www.coderage.com/" target="_top">CodeRage, LLC</a><br/>© Copyright 2004-2007 <a href="http://www.coderage.com/turkanis/" target="_top">Jonathan Turkanis</a></P>
<P CLASS="copyright">
Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <A HREF="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</A>)
</P>
<!-- End Footer -->
</BODY>
